/*
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 *
 * This software is open source.
 * See the bottom of this file for the licence.
 */

package com.googlecode.bluetools.dom4j.rule;

import java.util.ArrayList;
import java.util.Collections;

import com.googlecode.bluetools.dom4j.Node;

/**
 * <p>
 * <code>RuleSet</code> manages a set of rules which are sorted in order of relevance according to the XSLT defined
 * conflict resolution policy. This makes finding the correct rule for a DOM4J Node using the XSLT processing model
 * efficient as the rules can be evaluated in order of priority.
 * </p>
 * 
 * @author <a href="mailto:james.strachan@metastuff.com">James Strachan </a>
 * @version $Revision: 1.1 $
 */
public class RuleSet {
	/** An unordered list of Rule objects */
	private ArrayList rules = new ArrayList();

	/** A lazily evaluated and cached array of rules sorted */
	private Rule[] ruleArray;

	public RuleSet() {
	}

	public String toString() {
		return super.toString() + " [RuleSet: " + rules + " ]";
	}

	/**
	 * Performs an XSLT processing model match for the rule which matches the given Node the best.
	 * 
	 * @param node is the DOM4J Node to match against
	 * 
	 * @return the matching Rule or no rule if none matched
	 */
	public Rule getMatchingRule(Node node) {
		Rule[] matches = getRuleArray();

		for (int i = matches.length - 1; i >= 0; i--) {
			Rule rule = matches[i];

			if (rule.matches(node)) {
				return rule;
			}
		}

		return null;
	}

	public void addRule(Rule rule) {
		rules.add(rule);
		ruleArray = null;
	}

	public void removeRule(Rule rule) {
		rules.remove(rule);
		ruleArray = null;
	}

	/**
	 * Adds all the rules to this RuleSet from the given other rule set.
	 * 
	 * @param that DOCUMENT ME!
	 */
	public void addAll(RuleSet that) {
		rules.addAll(that.rules);
		ruleArray = null;
	}

	/**
	 * Returns an array of sorted rules.
	 * 
	 * @return the rules as a sorted array in ascending precendence so that the rules at the end of the array should be
	 *         used first
	 */
	protected Rule[] getRuleArray() {
		if (ruleArray == null) {
			Collections.sort(rules);

			int size = rules.size();
			ruleArray = new Rule[size];
			rules.toArray(ruleArray);
		}

		return ruleArray;
	}
}

/*
 * Redistribution and use of this software and associated documentation ("Software"), with or without modification, are
 * permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain copyright statements and notices. Redistributions must also contain a
 * copy of this document.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
 * following disclaimer in the documentation and/or other materials provided with the distribution.
 * 
 * 3. The name "DOM4J" must not be used to endorse or promote products derived from this Software without prior written
 * permission of MetaStuff, Ltd. For written permission, please contact dom4j-info@metastuff.com.
 * 
 * 4. Products derived from this Software may not be called "DOM4J" nor may "DOM4J" appear in their names without prior
 * written permission of MetaStuff, Ltd. DOM4J is a registered trademark of MetaStuff, Ltd.
 * 
 * 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org
 * 
 * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL METASTUFF, LTD. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 */
